This application claims the priority of Korean Patent Application No. 2004-97643, filed on Nov. 25, 2004, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to a mobile communication terminal and, more particularly, to a technology associated with booting up a mobile communication terminal equipped with a user identification module.
2. Description of Related Art
The user identification module has been introduced for more secure user identification as a measure against the use of counterfeit mobile phones or for the use of international roaming services. The user identification module refers to a detachable subscriber identification module (SIM) or user identification module (UIM). SIM has been introduced to an early GSM-based mobile communication system, while UIM has been developed for use in a CDMA-based mobile communication system by CDMA providers after the introduction of the GSM-based SIM.
The user identification module (which refers to the UIM used in the CDMA scheme in the present invention) is a smart card and comprises a microprocessor and a memory chip. The memory chip of UIM stores subscriber information, such as phone number, password, and billing, network registration information, which a user requires for using mobile communication services offered over a mobile communication network, phonebook data, short message service (SMS) data and the like.
In a conventional mobile communication terminal equipped with the UIM, it has taken a long time to copy a phonebook stored in UIM into RAM at boot time, causing a decrease in boot speed. First, a description will now be given of a process of copying a phonebook stored in ROM into RAM at the boot time of a conventional mobile communication terminal having no UIM with reference to FIG. 1.
FIG. 1 is a schematic block diagram showing a construction necessary for copying a phonebook stored in ROM into RAM at the boot time of a conventional mobile communication terminal. Upon power-on of the mobile communication terminal, a user interface (UI) task 100 displays an initial screen on a liquid crystal display (LCD) device which is a user interface. To copy a phonebook stored in ROM 120, which is a non-volatile (NV) memory, into RAM 130 during the boot process, the UI task 100 hands over controllership to a NV task 110 which is responsible for processing the NV memory. The NV task 110 accesses the ROM 120, reads one of records composing the phonebook, writes it to the RAM 130, and then hands over the controllership to the UI task 100. The UI task 100 and the NV task 110 continue to hand over the controllership to each other until all the records composing the phonebook stored in ROM 120 are copied. This is called a task switching, which is a process of handing over the controllership between tasks running on an operating system of a mobile communication terminal.
The conventional mobile communication terminal reads the records composing the phonebook stored in ROM one by one and copies the records into RAM at boot time. In a case of a phonebook composed of 250 records, task switching required for the 250 records in the conventional mobile communication terminal has little effect on the boot speed of the terminal. However, in a case of a mobile communication terminal equipped with UIM, the conventional technology of processing a phonebook at boot time has an effect on the boot speed, which will be described in detail with reference to FIG. 2. FIG. 2 is a schematic block diagram showing a construction necessary for copying a phonebook stored in a user identification module into RAM at the boot time of a conventional mobile communication terminal equipped with a UIM. The process of reading a phonebook stored in a UIM and copying it into RAM at the boot time of the mobile communication terminal equipped with the UIM shown in FIG. 2 is a process obtained by adding an additional algorithm to an existing task switching algorithm rather than by modifying the existing task switching algorithm.
The phonebook can be stored into ROM and/or UIM 130. A description will now be given of a process of reading the phonebook stored in the UIM 230 at boot time, which composes the gist of the present invention. First, upon power-on of a mobile communication terminal, a UI task 200 is activated and displays an initial screen on an LCD device which is a user interface. The UI task 200 hands over controllership to the NV task 210 for copying the phonebook stored in the UIM 230 into RAM 240 during the boot process. The NV task 210 performs a well-known initial process for accessing the UIM 230. That is, the NV task 210 determines what items to access and whether to read or write, and then sets corresponding parameters. In this case, suppose that a parameter necessary for reading the phonebook is set.
Next, the NV task 210 hands over the controllership to the UIM task 220. The UIM task 220, which has taken over the controllership and has been activated, reads one of records composing the phonebook from the UIM 230 linked with the UIM task 220, and hands over the controllership to the NV task 210. The NV task 210 copies the one of records composing the phonebook read from the UIM task 220 into RAM 240, and then hands over the controllership to the UI task 200. One of the records composing the phonebook is copied into RAM through the above-mentioned process, which needs four times of task switching. For example, in a case of a phonebook composed of 250 records, one thousand times of task switching should be performed since reading each record requires four times of task switching. Consequently, there is a problem in that so many times of task switching causes a decrease in boot speed.